President Donald Trump characterized a descending caravan of would-be Central American migrants making their way to the U.S. as a national emergency, in a Monday morning tweet.

Sadly, it looks like Mexico’s Police and Military are unable to stop the Caravan heading to the Southern Border of the United States. Criminals and unknown Middle Easterners are mixed in. I have alerted Border Patrol and Military that this is a National Emergy. Must change laws!

Trump lamented the limited effort the Mexican government has taken in attempting to quell the caravan of thousands of migrants as they continue to make their way through the country bound for the U.S. The president also expressed concern that “unknown middle easterners” and criminals were mixed in with the caravan.

Photo by John Moore/Getty Images

The caravan has swelled to nearly 5,000 people as it entered Mexico via Guatemala. The majority of the caravan consists of Central Americans who wish to gain entry to the U.S. by claiming asylum upon arrival.

Department of Homeland Security Kirstjen Nielsen warned Sunday that drug cartels could exploit the caravan for its own purposes. “While we closely monitor the caravan crisis, we must remain mindful of the transnational criminal organizations and other criminals that prey on the vulnerabilities of those undertaking the irregular migration journey,” she said.